The final assembly of large structures such as airplanes is typically performed on a factory floor where large scale components are moved into final assembly positions. In the case of an airplane, fuselage sections, wings and tail assemblies are placed on assembly jacks that are used to locate, align and move the components into their final assembly positions where they are permanently joined together. The processes for locating, aligning and moving the components are less than fully integrated and are performed primarily using manual operations which can introduce variations in final component alignment from airplane-to-airplane.
Slight variations of the final assembly positions of the airplane components from nominal positions may alter the relative orientation of aerodynamically significant features of the airplane such as wings and the vertical stabilizer. The orientation of these aerodynamically significantly features can affect the trimmed cruise configuration of the airplane, sometime also referred to as the “line-of-flight” of the airplane, which is used as a reference to initialize the airplane's electronic flight controls. Because of these variations, the line-of-flight must be established for each airplane, as-built. The process of establishing the line-of-flight for an as-built airplane normally involves estimations that may not completely reflect all variations in component alignment. As a result, flight controls may be required to trim rudder angle in a manner that results in less than maximum cruise efficiency, adding to fuel usage.
Accordingly, there is a need for a system for assembling large scale components of vehicles such as airplanes that is highly automated, improves assembly alignment and provides information relating to the relative orientation of aerodynamically significant feature that may affect the trimmed cruise configuration of the airplane. There is also a need for an assembly system that calculates the optimized trimmed cruise configuration of the as-built airplane, as well as a system for establishing a physical reference monument inside the airplane that represents the calculated cruise orientation.